Systems and methods for determining a power option for an access node

ABSTRACT

Systems and methods are described for determining a power option for an access node. Application requirements for a first plurality of wireless devices in communication with a first access node may be identified for each wireless device. The number of wireless devices that comprise a met application requirement may then be determined. When that number meets a first criteria, a plurality of power options for transmitting a first signal may be determined. For each power option, a second number of the first plurality of wireless devices and a third number of wireless devices in communication with a second access node may be estimated. Based on the estimated numbers for the determined power options, a power option may be selected and the first access node may transmit the first signal according to the selected power option.

TECHNICAL BACKGROUND

Telecommunication systems, such as cellular networks or other wirelessnetworks, use wireless signals to establish communication channelsbetween various network devices. For example, an access node maytransmit a reference signal or a pilot signal over a signal radius, andone or more wireless devices within the signal radius may attempt toestablish a connection with the access node based on the referencesignal.

In certain circumstances, it may be advantageous to boost or to increasethe power of the reference signal transmitted from an access node. Forexample, where a wireless device uses a reference signal for channelestimation, increasing the reference signal strength can improve channelquality. Accordingly, power boosting may be performed at an access nodesuch that the signal level of a reference signal, or pilot signal,transmitted by the access node is increased.

OVERVIEW

Systems and methods are described for determining a power option for anaccess node. A first plurality of wireless devices may be incommunication with an access node, and an application requirement may beidentified for each of the first plurality of wireless devices. A firstnumber of wireless devices from among the first plurality that comprisea met application requirement may be determined. When the number ofwireless devices with a met application requirement meets a firstcriteria, a plurality of power options for transmitting a first signalmay be determined.

For each power option, a second number of wireless devices from amongthe first plurality of wireless devices may be estimated, where theestimated second number of wireless device may comprise a metapplication requirement. In addition, for each power option, a thirdnumber of a third number of wireless devices in communication with asecond access node may be estimated, where the first signal transmittedaccording to each power option interferes with a communication betweenthe third number of wireless devices and the second access node. Basedon the estimated second numbers and the estimated third numbers for thedetermined power options, a power option may be selected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary communication system to determine apower option for an access node.

FIG. 2 illustrates another exemplary system to determine a power optionfor an access node.

FIG. 3 illustrates an exemplary method of determining a power option foran access node.

FIG. 4 illustrates another exemplary system to determine a power optionfor an access node.

FIG. 5 illustrates another exemplary system to determine a power optionfor an access node.

FIG. 6 illustrates another exemplary method of determining a poweroption for an access node.

FIG. 7 illustrates another exemplary method of selecting a power optionfor an access node.

FIG. 8 illustrates another exemplary method of determining a poweroption for an access node.

FIG. 9 illustrates a table used to determine a power option for anaccess node.

FIG. 10 illustrates another table used to determine a power option foran access node.

FIG. 11 illustrates another table used to determine a power option foran access node.

FIG. 12 illustrates another exemplary method of determining a poweroption for an access node.

FIG. 13 illustrates an exemplary processing node.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary communication system 100 to determine apower option for an access node comprising wireless devices 102 and 104,access nodes 106 and 108, communication network 110, and communicationlinks 112, 114, 116, 118, and 120. Other network elements may be presentin the communication system 100 to facilitate communication but areomitted for clarity, such as controller nodes, base stations, basestation controllers, gateways, mobile switching centers, dispatchapplication processors, and location registers such as a home locationregister or visitor location register. Furthermore, other networkelements may be present to facilitate communication between access node104, access node 106, and communication network 108 which are omittedfor clarity, including additional processing nodes, routers, gateways,and physical and/or wireless data links for carrying data among thevarious network elements.

Wireless devices 102 and 104 can be any device configured to communicateover communication system 100 using a wireless communication link. Forexample, wireless devices 102 and 104 can include a cell phone, a smartphone, a computing platform such as a laptop, palmtop, or a tablet, apersonal digital assistant, or an internet access device, andcombinations thereof. It is noted that while one wireless device isillustrated in FIG. 1 as being in communication with each of accessnodes 106 and 108, any number of wireless devices can be implemented.

Access nodes 106 and 108 are network nodes capable of providing wirelesscommunications to wireless device 102, and can be, for example, a basetransceiver station, a radio base station, an eNodeB device, or anenhanced eNodeB device. Access nodes 106 and 108 may communicate withcommunication network 110 over communication links 116 and 118. Accessnodes 106 and 108 may also communicate directly with each other overcommunication link 120. In an embodiment, access node 106 can comprise aserving access node for wireless device 102, and access node 108 cancomprise a serving access node for wireless device 104.

Although only two access nodes 106 and 108 are illustrated in FIG. 1,wireless devices 102 and 104 can be in communication with a plurality ofaccess nodes. The plurality of access nodes can be associated withdifferent networks and can support different communication protocols andradio access technologies.

Communication network 110 can be a wired and/or wireless communicationnetwork, and can comprise processing nodes, routers, gateways, andphysical and/or wireless data links for carrying data among variousnetwork elements, including combinations thereof, and can include alocal area network, a wide area network, and an internetwork (includingthe Internet). Communication network 110 can be capable of carryingvoice information and other information, for example, to supportcommunications by a wireless device such as wireless device 102.Wireless network protocols may comprise code division multiple access(CDMA) 1×RTT, Global System for Mobile communications (GSM), UniversalMobile Telecommunications System (UMTS), High-Speed Packet Access(HSPA), Evolution Data Optimized (EV-DO), EV-DO rev. A, Third GenerationPartnership Project Long Term Evolution (3GPP LTE), and WorldwideInteroperability for Microwave Access (WiMAX). Wired network protocolsthat may be utilized by communication network 110 comprise Ethernet,Fast Ethernet, Gigabit Ethernet, Local Talk (such as Carrier SenseMultiple Access with Collision Avoidance), Token Ring, Fiber DistributedData Interface (FDDI), and Asynchronous Transfer Mode (ATM).Communication network 110 may also comprise a wireless network,including base stations, wireless communication nodes, telephonyswitches, internet routers, network gateways, computer systems,communication links, or some other type of communication equipment, andcombinations thereof.

Communication links 112, 114, 116, 118, and 120 can be wired or wirelesscommunication links. Wired communication links can comprise, forexample, twisted pair cable, coaxial cable or fiber optic cable, orcombinations thereof. Wireless communication links can comprise a radiofrequency, microwave, infrared, or other similar signal, and can use asuitable communication protocol, for example, GSM, CDMA, UMTS, HSPA,WIMAX, EV-DO, WiMAX, or 3GPP LTE, or combinations thereof. Otherwireless protocols can also be used.

FIG. 2 illustrates an exemplary communication system 200 for determininga power option for an access node. System 200 comprises wireless devices202, 204, 206, 208, 210, and 212, access nodes 214 and 216. Wirelessdevices 202, 204, 206, 208, 210, and 212 may comprise devices similar towireless devices 102 and 104 illustrated in FIG. 1. Similarly, accessnodes 214 and 216 may comprise access nodes similar to access nodes 106and 108 illustrated in FIG. 1. Access node 214 comprises signal radii218 and 220, and access node 216 comprises signal radius 222.

A signal radius, or coverage radius, may comprise an area around anaccess node within which a wireless device can detect a signaltransmitted form the access node. Signal radii 218 and 220 can compriseradii for reference signals, or pilot signals, transmitted from accessnode 214, and signal radius 222 can comprise a radius for a referencesignal, or pilot signal, transmitted from access node 216.

In operation, wireless devices 202, 204, and 206 may establishcommunication with access node 214 such that access node 214 providesthe wireless devices access to a communication network (such ascommunication network 108, illustrated in FIG. 1). Access node 214 maytransmit a reference signal, or a pilot signal, over signal radius 218,to enable wireless devices 202, 204, and 206 to detect access node 214.When a wireless device, such as wireless device 202, detects thereference signal from access node 214, and it is determined that thereference signal from access node 214 meets a threshold signal level,wireless device 202 may attempt to establish communication with accessnode 214. For example, the signal level may be represented by receivedsignal strength indication (RSSI), reference signal received power(RSRP), reference signal received quality (RSRQ), signal to noise ratio(SINR), or any other suitable metric. Similarly, wireless devices 208,212, and 210 may establish communication with access node 216 such thataccess node 216 provides the wireless devices access to a communicationnetwork (such as communication network 108, illustrated in FIG. 1)

In an embodiment, wireless devices 202, 204, and 206 can compriseapplication requirements. An application requirement, or a quality ofservice (QoS) requirement, may be one or more service conditions that awireless device requests from an access node, such as a quality ofservice class identifier (QCI), a minimum guaranteed bit rate (GBR),maximum bit rate (MBR), a priority, a minimum bit rate, a maximumpermitted data delay, a minimum throughput, a maximum error rate, amaximum data loss rate, and any other application requirement. Forexample, wireless device 202 may request an application requirement fromaccess node 214.

In an embodiment, an access node may determine the number of wirelessdevices in communication with that access node that comprise metapplication requirements. For example, wireless devices 202, 204, and206 may request application requirements from access node 214. Accessnode 214 may determine which of wireless devices 202, 204, and 206comprise met application requirements. In an example, each of wirelessdevices 202, 204, and 206 may comprise a QCI and access node 214 maydetermine whether the service conditions for the QCIs are achieved.

In some instances, wireless devices that are located near an edge of asignal radius for an access node have a higher likelihood of comprisingunmet service conditions. For example, wireless devices located at theedge of a signal radius (e.g., a cell edge) may receive signalstransmitted from the access node at a lower signal level than wirelessdevices located closer to the access node. With reference to FIG. 2,wireless devices 202 and 204 may be located closer to access node 214than wireless device 206 (as depicted). Accordingly, the applicationrequirements for wireless devices 202 and 204 may be met while anapplication requirement for wireless device 206 may not be met. Inanother example, one or more application requirements for wirelessdevices 202, 204, 206 may be unmet due to congestion over communicationlinks between the wireless devices and access node 214. For example,access node 214 may not have the resources available to satisfy theunmet application requirements (e.g., due to a high volume of data sentto or from wireless device in communication with access node 214, or alarge number of wireless devices in communication with the access node,and the like).

In an embodiment, power boosting may be performed at an access node totransmit a signal, such as a reference signal or a pilot signal, fromthe access node with an increased signal level, which may increase thesignal radius of the signal. For example, power boosting may beperformed in a multi-antenna configuration according to the 3GPP LTEprotocol. An access node may comprise at least two antennas and mayimplement a Multiple Input Multiple Output (MIMO) protocol for sending(as well as receiving) signals. In an embodiment, when a first of the atleast two antennas is transmitting a reference signal, the secondantenna may not transmit a signal. Accordingly, when the first antennais transmitting a reference signal, power boosting of the referencesignal may be accomplished by using signal power of the second antennafor the reference signal transmitted from the first antenna. Othersuitable processes for increasing the transmitted signal level of areference signal may also be implemented.

In an embodiment, power boosting may be performed to transmit areference signal, or pilot signal, from an access node with an increasedsignal level, which may better satisfy application requirements ofwireless devices. For example, a reference signal according to the 3GPPLTE protocol may be used for channel estimation by wireless device, andthus a boost in the reference signal power can improve channel quality.These improved channel conditions can lead to a greater ability tosatisfy service conditions, and subsequently application requirements,for the wireless devices communicating with the access node.

With reference to FIG. 2, signal radius 218 may comprise a referencesignal radius for access node 214 when power boosting is not performed,while signal radius 220 may comprise a reference signal radius foraccess node 214 when power boosting is performed. In a first example,when power boosting is not performed, application requirements fromwireless device 206 may not be met because wireless device 206 islocated near the edge of signal radius 218 and, therefore, may detectthe reference signal transmitted from access node 214 at a low signallevel (e.g., below a threshold level required to satisfy the applicationrequirements from wireless device 206). In a second example, when powerboosting is performed, the application requirement wireless 206 may bemet since the signal radius 220 is larger than signal radius 218 andwireless device 206 may receive the reference signal from access node214 at a higher signal level when compared to the first example (e.g.,above a threshold level required to satisfy the application requirementsfrom wireless device 206).

Power boosting may be performed only on a reference signal, and may notbe performed for other signals transmitted from the access node, such asbearer signals, control signals, and the like. This can result in thereference signal radius of an access node being larger than the signalradius for other signals of the access node. In this example, a wirelessdevice that detects a reference signal from an access node performingpower boosting may be out of range for other signals transmitted by theaccess node. In addition, the wireless device which detects the boostedreference signal may be unable to transmit signals to the access node ata sufficient signal level to reach the access node performing powerboosting. In such case, a handover to the access node performing powerboosting may be attempted due to the increased reference single power,but this handover may fail because of the discrepancy in signal radiidescribed above. Additionally, this type of mismatch between referencesignal radius and other signal radii can result in service interruptionssuch as dropped calls, lagging or poor quality media streams, or otherservice interruptions.

In some scenarios, transmitting a reference signal with an increasedpower may negatively affect wireless devices communicating withneighboring access nodes. For example, a first access node may transmita reference signal with an increased signal radius and a wireless devicemay be in communication with a second access node that is adjacent tothe first access node. The reference signal transmitted with theincreased power form the first access node may have a greater area ofoverlap with a coverage area of the second access node. When thewireless device is located in an overlap area (e.g., an area that iswithin the reference signal radii for both the first access node and thesecond access node), wireless signals used in communication between thesecond access node and the wireless device may experience interferencefrom the first access node's reference signal due to the increasedsignal radius.

With reference to FIG. 2, wireless device 208 may be in communicationwith access node 216 and access node 216 may comprise signal radius 222.In an example, when access node 214 performs power boosting, theexpanded signal radius 220 for the reference signal transmitted fromaccess node 214 may overlap with signal radius 222. As illustrated,wireless device 208 may be located within signal radius 220 and signalradius 222. Subsequently, the reference signal transmitted with anincreased power from access node 214 may interfere with communicationbetween wireless device 208 and access node 216. For example, a handoverof wireless device 208 to access node 214 may be attempted based on thereference signal transmitted from access node 214 and detected atwireless device 208. Accordingly, wireless device 208 may commence ahandover process and attempt to communicate with access node 214 tocomplete the handover. The handover may then fail because wirelessdevice 208 may be out of range to perform the handover to access node214 (e.g., signals transmitted from wireless device 208 may not compriseradii large enough to reach access node 214 and/or signals other thanthe reference signal transmitted from access node 214 may not compriseradii large enough to reach wireless device 208). Note that wirelessdevices 210 and 212 may also be in communication with access node 216,however, the communication between wireless devices 210 and 212 andaccess nodes 216 may not be interfered with (or may be interfered withat a level below a threshold) because wireless devices 210 and 212 arenot located within signal radius 220.

In operation, a first plurality of wireless devices may be incommunication with an access node, and an application requirement may beidentified for each wireless device. A first number of wireless devicesthat comprise a met application requirement from among the firstplurality of wireless devices may then be determined. When the number ofwireless devices with a met application requirement meets a firstcriteria, a plurality of power options for transmitting a first signal,such as a reference signal or a pilot signal, may be determined. Eachpower option may comprise an option for transmitting a reference signalfrom the first access node with a particular power.

For each power option, a second number of the first plurality ofwireless devices that would comprise a met application requirement whenthe first access node performs the power option may be estimated. Inaddition, for each power option, a third number of wireless devices incommunication with a second access node may be estimated, where thefirst signal is projected to interfere with communication between thethird number wireless devices and the second access node when the firstaccess node performs the power option. Based on the estimated numbersfor the determined power options, a power option may be selected, andthe first access node may transmit the first signal according to theselected power option.

FIG. 3 illustrates an exemplary method for determining a power optionfor an access node. The method will be discussed with reference to theexemplary communication system 200 illustrated in FIG. 2, however, themethod can be implemented with any suitable communication system.

Referring to FIG. 3, at step 302, an application requirement for each ofa first plurality of wireless devices in communication with a firstaccess node is identified. For example, wireless devices 202, 204, and206 may be in communication with access node 214 and an applicationrequirement for each of wireless devices 202, 204, and 206 may beidentified. The application requirement may comprise a QCI, a GBR, aMBR, a priority, a minimum bit rate, a maximum permitted data delay, aminimum throughput, a maximum error rate, a maximum data loss rate, andany other suitable conditions. In an embodiment, applications running onwireless devices 202, 204, and 206 may be detected, and the identifiedapplication requirements may be based on the detected runningapplications.

At step 304, a first number of wireless devices from among the firstplurality of wireless devices is determined, where the first number ofwireless devices comprise application requirements that are met. Forexample, wireless devices 202, 204, and 206 may each send a request toaccess node 214 for uplink resources comprising a minimum bit rate tomeet application requirements of an application running on each ofwireless devices 202, 204, and 206. As another example, wireless devices202, 204, and 206 may request data for an application running on each ofwireless devices 202, 204, and 206 at a maximum permitted data delay, aminimum throughput, a maximum error rate, a maximum data loss rate, andthe like. Access node 214 may then determine whether the applicationrequirements for wireless devices 202, 204, and 206 can be met. Forexample, access node 214 may determine that the application requirementsfrom wireless devices 202 and 204 are met, while the applicationrequirement from wireless device 206 is not met.

At step 306, when the first number of wireless devices meets a firstcriteria, a plurality of power options for transmitting a first signalfrom the first access node are determined. For example, a plurality ofoptions for transmitting a signal, such as a reference signal or a pilotsignal, from access node 214 with an increased power (e.g., performingpower boosting) may be determined. The plurality of options may bedetermined when the first number of the first plurality of wirelessdevices meets a first criteria, such as when the first number is below athreshold amount (e.g., when the first number is less than 80% of thefirst plurality wireless devices).

In an embodiment, the determined power options may comprise options fortransmitting the first signal, such as a reference signal or pilotsignal, with a plurality of powers. In an example where an access nodecomprises a multi-antenna configuration, when a first antenna istransmitting a reference signal, power options may comprise: using powerfrom a first antenna to transmit the reference signal; using power froma first antenna and a second antenna to transmit the reference signal;using power from a first antenna, a second antenna, and a third antennato transmit the reference signal; using power from a first antenna, asecond antenna, a third antenna, and a fourth antenna to transmit thereference signal, and so on.

In an embodiment, a reference signal transmitted without a boosted power(e.g., using power form 1 antenna) may comprise a signal level of 1.5dB. The determined power options may comprise transmitting the referencesignal with a signal level of 1.5 dB (power from 1 antenna), 3 dB (powerfrom 2 antennas), 4.5 dB (power from 3 antennas), 6 dB (power from 4antennas), and so on. Other suitable processes for increasing the powerof a transmitted signal and determining power options may also beimplemented.

For each power option, a second number from among the first plurality ofwireless devices is estimated, where the second number of wirelessdevices comprise application requirements that are met (step 308). In anembodiment, a first access node may be in communication with a pluralityof wireless devices, where an application requirement for each wirelessdevice has been identified. An estimated second number for a poweroption may comprise the number of wireless devices that will have theapplication requirement for that wireless device met when the firstaccess node transmits a signal, such as a reference signal or pilotsignal, according to the power option

For example, four power options may be determined at step 306.Accordingly, a second number for each of the four power options may beestimated. When estimating for the first power option, based on thefirst access node transmitting the first signal with a power accordingto the first power option (e.g., a signal level of 1.5 dB), it may beestimated how many of the first plurality of wireless device will havetheir application requirement met. When estimating for the second poweroption, based on the first access node transmitting the first signalwith a power according to the second power option (e.g., a signal levelof 3 dB), it may be estimated how many of the first plurality ofwireless device will have their application requirement met. This may berepeated for each of the power options until a second number for each ofthe power options has been estimated.

At step 310, for each power option, a third number of wireless devicesin communication with a second access node is estimated, wherein thefirst signal transmitted according to each power option interferes witha communication between the third number of wireless devices and thesecond access node. In an embodiment, a first access node may be incommunication with a first plurality of wireless devices and a secondaccess node may be in communication with a second plurality of wirelessdevices, where the two access node are neighboring. An estimated thirdnumber for a power option may comprise a number of the second pluralityof wireless devices that will experience interference (e.g.,interference beyond a threshold level) when the first access nodetransmits a signal, such as a reference signal or pilot signal,according to the power option.

For example, four power options may be determined at step 306.Accordingly, a third number for each of the four power options may beestimated. When estimating for the first power option, based on thefirst access node transmitting the first signal with a power accordingto the first power option (e.g., a signal level of 1.5 dB), it may beestimated how many of the second plurality of wireless device willexperience interference (e.g., interference beyond a threshold level).In this example, the third number may be estimated based on ascertainedlocations for the second plurality of wireless devices and a projectedoverlap between signal radii for the first access node and the secondaccess node. When estimating for the second power option, based on thefirst access node transmitting the first signal with a power accordingto the second power option (e.g., a signal level of 3 dB), it may beestimated how many of the second plurality of wireless device willexperience interference (e.g., interference beyond a threshold level).This may be repeated for each of the power options until a third numberfor each of the power options has been estimated.

At step 312, a power option is selected based on the estimated secondnumbers and the estimated third numbers. In an embodiment, the estimatedsecond numbers and the estimated third numbers for each power option maybe weighed, and a power option may be selected based on the weighing.For example, for each power option, the estimated second number andestimated third number may be compared to criteria, and a power optionmay be selected based on the comparisons.

At step 314, the first signal may be transmitted according to theselected power option. For example, a first signal, such as a referencesignal or pilot signal, may be transmitted according to the selectedpower option. In this example, the power options may comprise aplurality signal levels for transmitting the first signal (e.g., 1.5 dB,3 dB, 4.5 dB, 6 dB, and the like), and the first signal may betransmitted with a signal level corresponding to the selected poweroption.

FIG. 4 illustrates another exemplary communication system 400 todetermine a communication access node for a wireless device.Communication system 400 may comprise a wireless devices 402, 404, and406 access nodes 408, 410, and 412, controller node 414, gateway node416, communication network 418, and communication links 420, 422, 424,426, 428, 430, 432, 434, 436, 438, 440, 442, and 444. Other networkelements may be present in the communication system 400 to facilitatecommunication but are omitted for clarity, such as base stations, basestation controllers, gateways, mobile switching centers, dispatchapplication processors, and location registers such as a home locationregister or visitor location register.

Wireless devices 402, 404, and 406 can be any device configured tocommunicate over communication system 400 using a wireless communicationlink. For example, wireless devices 402, 404, and 406 can include a cellphone, a smart phone, a computing platform such as a laptop, palmtop, ora tablet, a personal digital assistant, or an internet access device,and combinations thereof.

Access nodes 408, 410, and 412 are network nodes capable of providingwireless communications to wireless devices 402, 404, and 406, and canbe, for example, a base transceiver station, a radio base station, aneNodeB device, or an enhanced eNodeB device. In an embodiment, accessnode 408 can comprise a serving access node for wireless device 402,access node 410 can comprise a serving access node for wireless device404, and access node 410 can comprise a serving access node for wirelessdevice 406. Access nodes 408, 410, and 412 may communicate withcontroller node 414 over communication links 430, 432, and 434, and withgateway node 416 over communication links 436, 438, and 440. Accessnodes 408, 410, and 412 may also communicate directly with each otherover communication links 426 and 428.

Gateway node 416 is a network element which can comprise a processor andassociated circuitry to execute or direct the execution ofcomputer-readable instructions. Gateway node 416 may retrieve andexecute software from storage, which can include a disk drive, flashdrive, memory circuitry, or some other memory device, and which can belocal or remotely accessible. The software comprises computer programs,firmware, or some other form of machine-readable instructions, and mayinclude an operating system, utilities, drivers, network interfaces,applications, or some other type of software, including combinationsthereof. In an embodiment, gateway node 416 can provide instructions toaccess nodes 406, 404, and 408 related to channel selection incommunications with wireless devices 402, 404, and 406. For example,gateway node 416 can comprise at least one of a serving gateway (SGW), apacket data network gateway (PDNGW), a cellular gateway (CGW), and acombination thereof. Gateway node 416 may communicate with controllernode 414 over communication link 442 and with communication network 418over communication link 444.

Controller node 414 can comprise any network node configured to manageservices within system 400. Controller node 414 may provide othercontrol and management functions for system 400. For example, controllernode 414 can be further configured to determine a power option for anaccess node. The controller node 414 can comprise a single device havingvarious functions or a plurality of devices having differing functions.For example, controller node 414 can include at least one of amulti-cell/multicast coordination entity (MCE), a mobility managemententity (MME), a radio network controller (RNC), a mobile switchingcenter (MSC), and a combination thereof.

Controller node 414 can comprise a processor and associated circuitry toexecute or direct the execution of computer-readable instructions toobtain information. Controller node 414 can retrieve and executesoftware from storage, which can include a disk drive, a flash drive,memory circuitry, or some other memory device, and which can be local orremotely accessible. The software may comprise computer programs,firmware, or some other form of machine-readable instructions, and mayinclude an operating system, utilities, drivers, network interfaces,applications, or some other type of software, including combinationsthereof. Controller node 414 can receive instructions and other input ata user interface. Controller node 510 can comprise a processor andassociated circuitry to execute or direct the execution ofcomputer-readable instructions to obtain information.

Controller node 414 can retrieve and execute software from storage,which can include a disk drive, a flash drive, memory circuitry, or someother memory device, and which can be local or remotely accessible. Thesoftware may comprise computer programs, firmware, or some other form ofmachine-readable instructions, and may include an operating system,utilities, drivers, network interfaces, applications, or some other typeof software, including combinations thereof. Controller node 414 canreceive instructions and other input at a user interface.

Communication network 418 can be a wired and/or wireless communicationnetwork, and can comprise processing nodes, routers, gateways, andphysical and/or wireless data links for carrying data among variousnetwork elements, including combinations thereof, and can include alocal area network, a wide area network, and an internetwork (includingthe Internet). Communication network 418 may also comprise basestations, wireless communication nodes, telephony switches, internetrouters, network gateways, computer systems, communication links, orsome other type of communication equipment, and combinations thereof.Wireless network protocols may comprise code division multiple access(CDMA) 1×RTT, Global System for Mobile communications (GSM), UniversalMobile Telecommunications System (UMTS), High-Speed Packet Access(HSPA), Evolution Data Optimized (EV-DO), EV-DO rev. A, Third GenerationPartnership Project Long Term Evolution (3GPP LTE), and WorldwideInteroperability for Microwave Access (WiMAX). Wired network protocolsthat may be utilized by communication network 418 comprise Ethernet,Fast Ethernet, Gigabit Ethernet, Local Talk (such as Carrier SenseMultiple Access with Collision Avoidance), Token Ring, Fiber DistributedData Interface (FDDI), and Asynchronous Transfer Mode (ATM).

Communication links 420, 422, 424, 426, 428, 430, 432, 434, 436, 438,440, 442, and 444 can be wired or wireless communication links. Wiredcommunication links can comprise, for example, twisted pair cable,coaxial cable or fiber optic cable, or combinations thereof. Wirelesscommunication links can comprise a radio frequency, microwave, infrared,or other similar signal, and can use a suitable communication protocol,for example, Global System for Mobile telecommunications (GSM), CodeDivision Multiple Access (CDMA), Worldwide Interoperability forMicrowave Access (WiMAX), or Long Term Evolution (LTE), or combinationsthereof. Other wireless protocols can also be used.

Other network elements may be present in the communication system 400 tofacilitate wireless communication but are omitted for clarity, such asbase stations, base station controllers, gateways, mobile switchingcenters, dispatch application processors, and location registers such asa home location register or visitor location register. Furthermore,other network elements may be present to facilitate communication amongaccess nodes 408, 410, and 412, controller node 414, gateway node 416,and communication network 418 which are omitted for clarity, includingadditional processing nodes, routers, gateways, and physical and/orwireless data links for carrying data among the various networkelements.

FIG. 5 illustrates an exemplary communication system 500 for determininga power option for an access node. System 500 comprises a wirelessdevices 502, 504, 506, 508, 510, 512, 514, 516, 518, 520, 522, and 524,and access nodes 526, 528, and 530. Wireless devices 502, 504, 506, 508,510, 512, 514, 516, 518, 520, 522, and 524 may comprise devices similarto wireless device 402 of FIG. 4. Similarly, access nodes 526, 528, and530 may comprise access nodes similar to access nodes 408 of FIG. 4.

Access nodes 526, 528, and 530 may each transmit signals, such asreference signals or pilot signals, over signal radii. In an embodiment,access node 526 may transmit a signal according to a plurality of poweroptions. Accordingly, when access node 526 transmits the signalaccording to a first power option, the signal may comprise radius 532,when access node 526 transmits the signal according to a second poweroption, the signal may comprise radius 534, and when access node 526transmits the signal according to a third power option, the signal maycomprise radius 536. Access node 528 may transmit a signal over radius538 and access node 530 may transmit a signal over radius 540.

In an embodiment, wireless devices 502, 504, 506, 508, and 510 may be incommunication with access node 526, wireless devices 512, 516, and 522may be in communication with access node 528, and wireless devices 514,518, 520, and 524 may be in communication with access node 530. Wirelessdevices 502, 504, 506, 508, and 510 can comprise applicationrequirements, such as a minimum bit rate, that are requested from accessnode 526. Access node 526 may determine which of wireless devices 502,504, 506, 508, and 510 comprises met application requirements. Forexample, each of wireless devices 502, 504, 506, 508, and 510 maycomprise a minimum bit rate application requirement and access node 526may determine whether the service conditions for the minimum bit ratesare achieved.

In some instances, wireless devices that are located near an edge of asignal radius for an access node have a higher likelihood of comprisingunmet service conditions. With reference to FIG. 5, wireless devices502, 504, and 506 may be located closer to access node 526 than wirelessdevices 508 and 510 (as depicted). Accordingly, the applicationrequirements for wireless devices 502, 504, and 506 may be met whileapplication requirements for wireless devices 508 and 510 may not bemet. In another example, one or more application requirements forwireless devices 502, 504, 506, 508, and 510 may be unmet due to radiocongestion. For example, access node 526 may not have the resourcesavailable to meet the application requirements (e.g., due to a highvolume of wireless devices in communication with the access node).

In an embodiment, power boosting may be performed at an access node as apotential mitigation against unmet application requirements. Withreference to FIG. 5, access node 526 may perform power boosting totransmit a reference signal, or pilot signal, from an access node withan increased signal level such that the power boosting increases thesatisfaction of unmet application requirements. Access node 526 maytransmit the signal according to a plurality of power options. Forexample, when access node 526 transmits the signal according to a firstpower option, the signal may comprise radius 532, when access node 526transmits the signal according to a second power option, the signal maycomprise radius 534, and when access node 526 transmits the signalaccording to a third power option, the signal may comprise radius 536.

In some scenarios, transmitting a reference signal with an increasedpower may cause interference with wireless devices communicating withneighboring access nodes. For example, when power boosting is performedand the reference signal radius for an access node is expanded, othersignals transmitted from the access node, such as bearer signals,control signals, and any other suitable signals, may not comprise suchan expanded radius. In such case, a handover to the access nodeperforming power boosting may be attempted due to the increasedreference single power, but this handover may fail because of thediscrepancy in signal radii described above. Additionally, this type ofmismatch between reference signal radius and other signal radii canresult in service interruptions such as dropped calls, lagging or poorquality media streams, or other service interruptions.

In some scenarios, transmitting a reference signal with an increasedpower may negatively affect wireless devices communicating withneighboring access nodes. For example, a first access node may transmita reference signal with an increased signal radius and a wireless devicemay be in communication with a second access node that is adjacent tothe first access node. The reference signal transmitted with theincreased power form the first access node may have a greater area ofoverlap with a coverage area of the second access node. When thewireless device is located in an overlap area (e.g., an area that iswithin the reference signal radii for both the first access node and thesecond access node), wireless signals used in communication between thesecond access node and the wireless device may experience interferencefrom the first access node's boosted reference signal.

With reference to FIG. 5, when performing the second power option,signal radius 534 may overlap with signal radius 538 and signal radius540. Subsequently, the reference signal transmitted with an increasedpower from access node 526 may interfere with communication betweenwireless device 512 and access node 528 and between wireless device 514and access node 530. For example, a handover of wireless device 512 toaccess node 526 may be attempted based on the reference signaltransmitted from access node 526 and detected at wireless device 512.Accordingly, wireless device 512 may commence a handover process andattempt to communicate with access node 526 to complete the handover.The handover may then fail because wireless device 512 may be out ofrange to perform the handover to access node 526 (e.g., signalstransmitted from wireless device 512 may not comprise radii large enoughto reach access node 526 and/or signals other than the reference signaltransmitted from access node 526 may not comprise radii large enough toreach wireless device 512).

Similarly, when performing the third power option, signal radius 536 mayoverlap with signal radius 538 and signal radius 540. Subsequently, thereference signal transmitted with an increased power from access node526 may interfere with communication between wireless device 512 andaccess node 528, wireless device 516 and access node 528, wirelessdevice 514 and access node 530, wireless device 518 and access node 530,and wireless device 520 and access node 530.

In an embodiment, a power option may be selected for transmitting asignal, such as a reference signal or pilot signal, from an access node.For example, the selection may be based on estimated applicationrequirements that would be met by the selected power option andestimated interference that may be caused by the selected power option.FIG. 6 further describes an exemplary method for selecting such a poweroption.

FIG. 6 illustrates an exemplary method for determining a power optionfor an access node. The method will be discussed with reference to theexemplary communication system 500 illustrated in FIG. 5, however, themethod can be implemented with any suitable communication system.

Referring to FIG. 6, at step 602, applications running on wirelessdevices in communication with an access node are detected. For example,wireless devices 502, 504, 506, 508, and 510 may be in communicationwith access node 526 and applications running on the wireless devicesmay be detected. The detected application may be, for instance, a Voiceover IP (VoIP) application, a media streaming application, a messagingapplication, a web browser, or any other suitable application that isused to communicate over a network.

Referring to FIG. 6, at step 604, an application requirement for each ofa first plurality of wireless devices in communication with a firstaccess node is identified. For example, an application requirement foreach of wireless devices 502, 504, 506, 508, and 510 may be identified.The application requirements may comprise a QCI, a GBR, a MBR, apriority, a minimum bit rate, a maximum permitted data delay, a minimumthroughput, a maximum error rate, a maximum data loss rate, and anyother suitable requirement.

In an embodiment, the identified application requirement for each of thefirst plurality of wireless devices may be based on the detectedapplications running on the first plurality of wireless devices. Forexample, an application detected to be running on wireless device 502,such as a VoIP application, may be associated with an applicationrequirement, such as a minimum bit rate. Accordingly, the identifiedapplication requirement from wireless device 502 may comprise a minimumbit rate associated with the running VoIP application. In otherexamples, a plurality of applications may be running on wireless device502 and the application requirements from wireless device 502 maycomprise a plurality of application requirements associated with therunning applications.

At step 606, a first number of wireless devices from among the firstplurality of wireless devices is determined, where the first number ofwireless devices comprise application requirements that are met. Forexample, wireless devices 502, 504, 506, 508, and 510 may each requestan application requirement, such as a minimum bit rate requirement, fromaccess node 526. Access node 526 may then determine whether the serviceconditions for the application requirements from wireless devices 502,504, 506, 508, and 510 are met. For example, access node 526 maydetermine that the application requirements from wireless devices 502,504 and 506 are met, while the application requirements from wirelessdevices 508 and 510 are not met.

At step 608, when the first number meets a first criteria, a pluralityof power options for transmitting a first signal from the first accessnode are determined. For example, a plurality of power options fortransmitting a signal, such as a reference signal or a pilot signal,from access node 526 with an increased power (e.g., performing powerboosting) may be determined. The plurality of options may be determinedwhen the first number of the first plurality of wireless devices meets afirst criteria, such as when the first number is below a thresholdamount (e.g., when the first number is less than 80% of the firstplurality wireless devices).

In an embodiment, the determined options may comprise options fortransmitting the first signal, such as a reference signal or pilotsignal, with a plurality of powers. In an example where an access nodecomprises a multi-antenna configuration, when a first antenna istransmitting a reference signal, power options may comprise: using powerfrom a first antenna to transmit the reference signal; using power froma first antenna and a second antenna to transmit the reference signal;using power from a first antenna, a second antenna, and a third antennato transmit the reference signal; using power from a first antenna, asecond antenna, a third antenna, and a fourth antenna to transmit thereference signal, and so on.

In an embodiment, a reference signal transmitted without a boosted power(e.g., using power from one antenna) may comprise a signal level of 1.5dB. The power options may comprise transmitting the reference signalwith a signal level of 1.5 dB (power from 1 antenna), 3 dB (power from 2antennas), 4.5 dB (power from 3 antennas), 6 dB (power from 4 antennas),and so on. Other suitable processes for increasing the power of atransmitted signal and determining power options may also beimplemented.

For each power option, a second number from among the first plurality ofwireless devices is estimated, where the second number of wirelessdevices comprise application requirements that are met (step 610). In anembodiment, a first access node may be in communication with a pluralityof wireless devices, where an application requirement for each wirelessdevice has been identified. An estimated second number for a poweroption may comprise the number of wireless devices that will have theapplication requirement for that wireless device met when the firstaccess node transmits a signal, such as a reference signal or pilotsignal, according to the power option.

For example, four power options may be determined at step 608.Accordingly, a second number of wireless devices for each of the fourpower options may be estimated. When estimating for the first poweroption, based on the first access node transmitting the first signalwith a power according to the first power option (e.g., a signal levelof 1.5 dB), it may be estimated how many of the first plurality ofwireless device will have their application requirement met. Whenestimating for the second power option, based on the first access nodetransmitting the first signal with a power according to the second poweroption (e.g., a signal level of 3 dB), it may be estimated how many ofthe first plurality of wireless device will have their applicationrequirement met. This may be repeated for each of the power optionsuntil a second number for each of the power options has been estimated.

At step 612, locations are ascertained for wireless devices that are incommunication with neighboring access nodes. For example, locations maybe ascertained for wireless devices 512, 516, and 522 in communicationwith access node 528 and for wireless devices 514, 518, 520, and 524 incommunication with access node 530. In an embodiment, the locations maybe ascertained based on the signal level for one or more detectedsignals. For example, wireless device 516 may receive one or moresignals (e.g., reference signals or pilot signals) at a signal levelfrom at least one of access node 526, access node 528, and access node530. The signal level may be represented by RSSI, RSRP, RSRQ, SINR, orany other suitable metric. Based on the signal levels detected from atleast one of access node 526, 528, and 530, wireless device 516'sdistance from the access nodes may be estimated. Where a signal isdetected from at least two access nodes, the ascertained location ofwireless device 516 may be based on signal triangulation of the signals.

In another embodiment, the ascertained location of wireless device 516may be based on sectors for one or more of access nodes 526, 528, and530. For example, an access node may be split into multiple sectors(e.g., 3 sectors measuring 120 degree arcs), and one or more signals maybe transmitted over each sector (e.g., a reference signal or pilotsignal). Accordingly, wireless device 516 may detect a signal fromaccess node 528 and a location may be ascertained for wireless device516 based on the sector associated with the detected signal. In anembodiment, a location may be ascertained for wireless device 516 basedon both the signal levels detected at the wireless device for signalsfrom at least one of access nodes 526, 528 and 530 and the sectorsassociated with those detected signals.

At step 614, for each power option, an overlap area is estimated. In anembodiment, a coverage radius may be determined for a first signal. Forexample, a coverage radius may be determined for the first signaltransmitted from access node 526 (e.g. signal radius 532). In thisexample, four power options may be determined at step 608. For eachpower option, an increased coverage radius of the first signal may beestimated. For example, for the second power option (e.g., transmittinga reference signal with a 3 dB signal level), an increased coverageradius may be estimated (e.g., increased signal radius 534). An overlaparea may then be determined between the increased coverage radius forthe first signal from access node 526 and signal radii from neighboringaccess nodes (e.g., signal radius 538 from access node 528 and signalradius 540 from access node 530). As illustrated, the determined overlaparea may comprise overlap between estimated signal radius 534 and signalradius 538 and the overlap between estimated signal radius 534 andsignal radius 540.

At step 616, for each power option, a third number of wireless devicesin communication with a second access node is estimated, wherein thefirst signal transmitted according to each power option interferes witha communication between the third number of wireless devices and thesecond access node. In an embodiment, a first access node may be incommunication with a first plurality of wireless devices and a secondaccess node may be in communication with a second plurality of wirelessdevices, where the two access node are neighboring. An estimated thirdnumber for a power option may comprise a number of the second pluralityof wireless devices that will experience interference (e.g.,interference beyond a threshold level) when the first access nodetransmits a signal, such as a reference signal or pilot signal,according to the power option.

For example, four power options may be determined at step 608.Accordingly, a third number for each of the four power options may beestimated. When estimating for the first power option, based on thefirst access node transmitting the first signal with a power accordingto the first power option (e.g., a signal level of 1.5 dB), it may beestimated how many of the second plurality of wireless device willexperience interference (e.g., interference beyond a threshold level).When estimating for the second power option, based on the first accessnode transmitting the first signal with a power according to the secondpower option (e.g., a signal level of 3 dB), it may be estimated howmany of the second plurality of wireless device will experienceinterference (e.g., interference beyond a threshold level). In theseexamples, the estimated interference may comprise failed handovers basedon the detected first signal or interference of wireless signals usedfor communication between the second plurality of wireless devices andthe neighboring access nodes (e.g., signal interference above athreshold). This may be repeated for each of the power options until athird number for each of the power options has been estimated.

In an embodiment, the third number of wireless devices may be estimatedbased on ascertained locations for the second plurality of wirelessdevices and a determined overlap area. For example, at step 612,locations may be ascertained for a second plurality of wireless devicesthat are in communication with neighboring access nodes. At step 614,for each power option, an overlap area may be estimated. For aparticular power option, the estimated third number of wireless devicesmay comprise the subset of the second plurality of wireless devices thatcomprise ascertained locations within the determined overlap area forthat power option. Because the ascertained locations for the wirelessdevices are within the determined overlap area, it may be projected thatthese wireless devices will experience interference.

At step 618, the estimated second number and the estimated third numberfor each power option are weighed. For example, for each power option,the estimated second number and estimated third number may be comparedto criteria. FIGS. 7-11 further illustrate the weighing of poweroptions.

At step 620, a power option is selected based on the estimated secondnumber and the estimated third number. For example, a power option maybe selected based on the weighing at step 618. At step 622, the firstsignal may be transmitted according to the selected power option. Forexample, a first signal, such as a reference signal or pilot signal, maybe transmitted according to the selected power option. In this example,the power options may comprise a plurality signal levels fortransmitting the first signal (e.g., 1.5 dB, 3 dB, 4.5 dB, 6 dB, and thelike), and the first signal may be transmitted with a signal levelcorresponding to the selected power option.

FIGS. 7 and 8 illustrate exemplary methods for weighing power options.The methods will be discussed with reference to the exemplarycommunication system 500 illustrated in FIG. 5, however, the method canbe implemented with any suitable communication system. The methods ofFIGS. 7 and 8 may be implemented with the method of FIG. 6. For example,step 618 of FIG. 6 may comprise the method steps of FIGS. 7 and 8.

Referring to FIG. 7, at step 702, for each power option, it isdetermined whether the estimated second number meets a second criteriaand whether the estimated third number meets a third criteria. Forexample, where four power options are determined, the estimated secondnumber of wireless devices for each power option may be compared to asecond criteria and the estimated third number of wireless devices foreach power option may be compared to a third criteria.

In an embodiment, the second number of wireless devices and the thirdnumber of wireless devices may comprise a percentage. For instance, thesecond number may comprise a percentage of wireless devices incommunication with access node 526 that comprise met applicationrequirements when a particular power option is performed. The thirdnumber may comprise a percentage of wireless devices in communicationwith access nodes that neighbor access node 526 (e.g., access node 528and access node 530) that experience interference when a particularpower option is performed.

FIG. 9 depicts tables 902, 904, and 906 for weighing power options.Table 902 comprises four power options, an estimated second number foreach power option, and an estimated third number for each power option.The estimated second numbers and the estimated third number arerepresented as percentages. In an embodiment, the second criteria maycomprise a lower-bound percentage for the second number and the thirdcriteria may comprise an upper-bound percentage for the third number.Table 904 comprises the second criteria and the third criteria, wherethe criteria are represented as percentages.

In the depicted example, the first power option comprises an estimatedsecond number of 75 and an estimated third number of 5, the second poweroption comprises an estimated second number of 75 and an estimated thirdnumber of 15, the third power option comprises an estimated secondnumber of 85 and an estimated third number of 20, and the fourth poweroption comprises an estimated second number of 90 and an estimated thirdnumber of 30. The second criteria comprises a lower-bound percentage of75 for the estimated second numbers and the third criteria comprises anupper-bound percentage of 25 for the estimated third numbers.

The first power option meets the criteria since the estimated secondnumber of 75 meets the second criteria of 75 and the estimated thirdnumber of 5 meets the third criteria of 25. The second power optionmeets the criteria since the estimated second number of 75 meets thesecond criteria of 75 and the estimated third number of 15 meets thethird criteria of 25. The third power option meets the criteria sincethe estimated second number of 85 meets the second criteria of 75 andthe estimated third number of 20 meets the third criteria of 25. Thefourth power option does not meet the criteria. Although the estimatedsecond number of 90 meets the second criteria of 75, the estimated thirdnumber of 30 does not meet the third criteria of 25.

At step 702, when, for at least one power option, the estimated secondnumber meets the second criteria and the estimated third number meetsthe third criteria, the method progresses to step 704. When no poweroption has an estimated second number that meets the second criteria andan estimated third number that meets the third criteria, the methodprogresses to the method of FIG. 8. In the example depicted by FIG. 9,the first, second, and third power options comprise an estimated secondnumber that meets the second criteria and an estimated third number thatmeets the third criteria. Accordingly, in this example, the methodprogresses to step 704.

At step 704, it is determined whether more than one power optioncomprises an estimated second number that meets the second criteria andan estimated third number that meets the third criteria. When one poweroption comprises estimated numbers that meet the criteria, the methodprogresses to step 706. At step 706, the one power option is selected.In the example depicted in FIG. 9, the first, second, and third poweroptions comprise estimated numbers that meet the criteria. Here, thefirst, second, and third power options may comprise a subset of poweroptions that meet the criteria. Accordingly, in this example, the methodprogresses to step 708.

At step 708, for each power option that meets the criteria, a firstdifference is calculated between the second number and the secondcriteria. In this example, the difference is calculated as EstimatedSecond Number−Second Criteria=First Difference. Accordingly, asillustrated in table 906, the first differences comprise 0, 0, and 10for the first power option, second power option, and third power option,respectively.

At step 710, for each power option that meets the criteria, a seconddifference is calculated between the third number and the thirdcriteria. In this example, the difference is calculated as ThirdCriteria−Estimated Third Number=Second Difference. Accordingly, asillustrated in table 906, the second differences comprise 20, 10, and 5for the first power option, second power option, and third power option,respectively.

At step 712, for each power option that meets the criteria, the firstdifference is multiplied by a first weight. For example, table 904illustrates the first weight as 1.25. A first weight greater than 1 mayindicate that the second number is to be weighed more heavily than thethird number and a first weight less than 1 may indicate that the secondnumber is to be weighed less heavily than the third number. The weightedfirst difference may be calculated as First Difference*FirstWeight=Weighted First Difference. Accordingly, as illustrated in table906, the weighted first differences comprise 0, 0, and 12.5 for thefirst power option, second power option, and third power option,respectively.

At step 714, for each power option that meets the criteria, the seconddifference is multiplied by a second weight. For example, table 904 ofFIG. 9 depicts the second weight as 0.75. A second weight greater than 1may indicate that the third number is to be weighed more heavily thanthe second number and a second weight less than 1 may indicate that thethird number is to be weighed less heavily than the second number. Theweighted second difference may be calculated as Second Difference*SecondWeight=Weighted Second Difference. Accordingly, as illustrated in table906, the weighted second differences comprise 15, 7.5, and 3.75 for thefirst power option, second power option, and third power option,respectively.

At step 716, a sum of the weighted first difference and the weightedsecond difference is calculated. For example, as illustrated in table906, the sums may comprise 15, 7.5, and 16.25 for the first poweroption, second power option, and third power option, respectively. Atstep 718, the power option with the greatest sum is selected. Forexample, the third power option may be selected because it comprises thegreatest sum. Accordingly, access node 526 may transmit the first signalaccording to the third power option.

FIG. 10 illustrates another example of weighing power options. Forexample, table 1002 illustrates that the first power option comprises anestimated second number of 75 and an estimated third number of 5, thesecond power option comprises an estimated second number of 75 and anestimated third number of 15, the third power option comprises anestimated second number of 85 and an estimated third number of 20, andthe fourth power option comprises an estimated second number of 90 andan estimated third number of 30. Table 1004 illustrates that the secondcriteria comprises a lower-bound percentage of 90 for the estimatedsecond numbers and the third criteria comprises an upper-boundpercentage of 5 for the estimated third numbers.

Referring to FIG. 7, at step 702, it is determined that none of thepower options comprise an estimated second number that meets the secondcriteria and an estimated third number that meets the third criteria.Accordingly, the method may progress to FIG. 8.

At step 802, for each power option, a first difference is calculatedbetween the second number and the second criteria. In this example, thedifference is calculated as Second Criteria−Estimated SecondNumber=First Difference. Accordingly, as illustrated in table 1006, thefirst differences comprise 15, 15, 5 and 0 for the first power option,second power option, third power option, and the fourth power option,respectively.

At step 804, for each power option, a second difference is calculatedbetween the third number and the third criteria. In this example, thedifference is calculated as Estimated Third Number−Third Criteria=SecondDifference. Accordingly, as illustrated in table 1006, the seconddifferences comprise 0, 10, 15 and 20 for the first power option, secondpower option, and third power option, and fourth power option,respectively.

At step 806, for each power option, the first difference is multipliedby a first weight. For example, table 1004 illustrates the first weightas 1.25. The weighted first difference may be calculated as FirstDifference*First Weight=Weighted First Difference. Accordingly, asillustrated in table 1006, the weighted first differences comprise18.75, 18.75, 6.25, and 0 for the first power option, second poweroption, third power option, and fourth power option, respectively.

At step 808, for each power option, the second difference is multipliedby a second weight. For example, table 1004 illustrates the secondweight as 0.75. The weighted second difference may be calculated asSecond Difference*Second Weight=Weighted Second Difference. Accordingly,as illustrated in table 1006, the weighted second differences comprise0, 7.5, 11.25, and 18.75 for the first power option, second poweroption, third power option, and fourth power option, respectively.

At step 810, for each power option, a sum of the weighted firstdifference and the weighted second difference is calculated. Forexample, as illustrated in table 1006, the sums may comprise 18.75,26.25, 17.25, and 18.75 for the first power option, second power option,third power option, and fourth power option, respectively. At step 812,the power option with the least sum is selected. For example, the thirdpower option may be selected because it comprises the least sum.Accordingly, access node 526 may transmit the first signal according tothe third power option.

It should be noted that the first difference and second difference arecalculated differently in the methods of FIGS. 7 and 8. For example, inthe method of FIG. 7, the calculations comprise: Estimated SecondNumber−Second Criteria=First Difference and Third Criteria−EstimatedThird Number=Second Difference. In the method of FIG. 8, thecalculations comprise Second Criteria−Estimated Second Number=FirstDifference and Estimated Third Number−Third Criteria=Second Difference.This can account for the difference of selecting the power option withthe greatest sum in the method of FIG. 7 but selecting the power optionwith the least sum in the method of FIG. 8.

FIG. 11 illustrates another example of weighing power options. Forexample, table 1102 illustrates that the first power option comprises anestimated second number of 75 and an estimated third number of 5, thesecond power option comprises an estimated second number of 75 and anestimated third number of 15, the third power option comprises anestimated second number of 85 and an estimated third number of 20, andthe fourth power option comprises an estimated second number of 90 andan estimated third number of 30. Table 1104 illustrates that the secondcriteria comprises a lower-bound percentage of 90 for the estimatedsecond numbers and the third criteria comprises an upper-boundpercentage of 10 for the estimated third numbers.

Referring to FIG. 7, at step 702, it is determined that none of thepower options comprise an estimated second number that meets the secondcriteria and an estimated third number that meets the third criteria.Accordingly, the method may progress to FIG. 8.

Similar to the descriptions for FIG. 8 herein, the steps 802-810 may beperformed until table 1106 comprises the First Difference, SecondDifference, Weighted First Difference, Weighted Second Difference andSums for the power options as illustrated. Here, it should be noted thatpower option 1 comprises a negative second difference. This is becausethe calculation comprises Estimated Third Number−Third Criteria=SecondDifference (e.g., 5−10=−5). Accordingly, when performing the methodsteps of FIG. 8, if an estimated third number is below the thirdcriteria (e.g., lower-bound for the third number), the subsequent seconddifference is negative. Similarly, if an estimated second number isabove the second criteria (e.g., upper-bound for the second number), thesubsequent first difference is negative. In this example, the thirdpower option comprises the least sum and the third power option may beselected.

In an embodiment, the first weight and the second weight may be adjustedsuch that the selected power option is adjusted. For example, the firstweight may be used to weigh the met application requirements for a firstplurality of wireless devices (e.g., the estimated second number). Thesecond weight may be used to weigh the interference for a secondplurality of wireless devices (e.g., the estimated third number).Accordingly, the weights may be adjusted to adjust how these elementsare balanced.

In an embodiment, the second criteria and the third criteria may beadjusted such that the selected power option is adjusted. For example,the second criteria may comprise a lower-bound for the number ofwireless device among a first plurality of wireless devices thatcomprise a met application requirement (e.g., the second number ofwireless devices). The third criteria may comprise an upper-bound forthe number of wireless devices among a second plurality of wirelessdevices that experience interference (e.g., the third number of wirelessdevices). Accordingly, the criteria may be adjusted to adjust thesebounds.

In an embodiment, one or more of the second criteria, the thirdcriteria, the first weight, and the second weight may be adjusted basedon the type of application requirements for the first plurality ofwireless devices. For example, a fourth number of wireless devices fromamong the first plurality of wireless devices may be determined, wherethe fourth number of wireless devices comprise application requirementsthat meet an application requirement criteria. The applicationrequirement criteria may comprise one or more of a QCI greater than athreshold, a GBR greater than a threshold, a minimum bit rate greaterthan a threshold, a maximum permitted data delay less than a threshold,a minimum throughput greater than a threshold, a maximum error rate lessthan a threshold, and a maximum data loss rate less than a threshold. Inan embodiment, based on the fourth number of wireless devices meeting afifth criteria, one of more of the second criteria, the third criteria,the first weight, and the second weight may be adjusted. For example,the application criteria may comprise of application requirements thatrequest resource intensive services. For instance, applicationrequirements that comprise high minimum bit rates, low data loss and/orerror rates, low data delay, and the like. Applications such as VoIPapplications or media streaming applications may comprise suchapplication requirements. In this example, the first weight may beincreased such that meeting the applications requirements for the firstplurality of wireless devices comprises an increased weight and/or thesecond criteria may be increased such that the lower-bound for thesecond number of wireless devices is increased.

FIG. 12 illustrates an exemplary method for determining a power optionfor an access node. The method will be discussed with reference to theexemplary communication system 500 illustrated in FIG. 5, however, themethod can be implemented with any suitable communication system. Themethod of FIG. 12 may be implemented after the method of FIG. 6. Forexample, step 622 of FIG. 6 may be followed by step 1202 of FIG. 12.

Referring to FIG. 12, at step 1202, an updated application requirementfor each of a first plurality of wireless devices in communication witha first access node is identified. For example, an updated applicationrequirement for each of wireless devices 502, 504, 506, 508, and 510 maybe identified. The updated application requirement may comprise a QCI, aGBR, a MBR, a priority, a minimum bit rate, a maximum permitted datadelay, a minimum throughput, a maximum error rate, a maximum data lossrate, and any other suitable requirement. The updated applicationrequirements may be identified similar to the manner in which theapplication requirements are identified at step 604 of FIG. 6.

At step 1204, for each power option, an updated second number from amongthe first plurality of wireless devices that comprise applicationrequirements that are met is estimated. An updated estimated secondnumber for a power option may comprise an updated number of wirelessdevices that will have the updated application requirement for thatwireless device met when the first access node transmits a signal, suchas a reference signal or pilot signal, according to the power option.The updated estimated second number may be estimated similar to themanner in which the second number is estimated at step 610 of FIG. 6.

At step 1206, updated locations are ascertained for wireless devicesthat are in communication with neighboring access nodes. For example,updated locations may be ascertained for wireless devices 512, 516, and522 in communication with access node 528 and for wireless devices 514,518, 520, and 524 in communication with access node 530. In anembodiment, the updated locations may be ascertained based on the signallevel for one or more detected signals. The updated locations may beascertained similar to the manner in which the locations are ascertainedat step 612 of FIG. 6.

At step 1208, for each power option, an updated third number of wirelessdevices in communication with a second access node is estimated, whereinthe first signal transmitted according to the power option interfereswith a communication between the updated third number of wirelessdevices and the second access node. In an embodiment, a first accessnode may be in communication with a first plurality of wireless devicesand a second access node may be in communication with a second pluralityof wireless devices, where the two access node are neighboring. Anupdated estimated third number for a power option may comprise a numberof the second plurality of wireless devices that will experienceinterference (e.g., interference beyond a threshold level) when thefirst access node transmits a signal, such as a reference signal orpilot signal, according to the power option. The updated estimated thirdnumber may be estimated similar to the manner in which the third numberis estimated at step 616 of FIG. 6.

At step 1210, the updated estimated second number and the updatedestimated third number for each power option are weighed. For example,for each power option, the updated estimated second number and updatedestimated third number may be compared to criteria. The updatedestimated second number and the updated estimated third number for eachpower option may be weighed similar to the manner in which the estimatednumbers are weighed at step 618 of FIG. 6.

At step 1212, a selected power option is adjusted based on the updatedestimated second number and the updated estimated third number. Forexample, an updated power option may be selected based on the weighingat step 1210. Accordingly, the previously selected power option may beadjusted to the updated selected power option. At step 1214, the firstsignal may be transmitted according to the updated selected poweroption. For example, a first signal, such as a reference signal or pilotsignal, may be transmitted according to the updated selected poweroption. In this example, the power options may comprise a pluralitysignal levels for transmitting the first signal (e.g., 1.5 dB, 3 dB, 4.5dB, 6 dB, and the like), and the first signal may be transmitted with asignal level corresponding to the selected power option.

In an embodiment, a power option may be selected based on the method ofFIG. 6, and the method of FIG. 12 may be performed to adjust theselected power option at some point in time after the method of FIG. 6is performed. For example, the method of FIG. 6 may be performed andafter a predetermined period of time, the method of FIG. 12 may beperformed.

Although the methods described perform steps in a particular order forpurposes of illustration, the methods discussed herein are not limitedto any particular order or arrangement. One skilled in the art, usingthe disclosure provided herein, will appreciate that various steps ofthe methods can be omitted, rearranged, combined, and/or adapted invarious ways.

FIG. 13 illustrates an exemplary processing node 1300 in a communicationsystem. Processing node 1300 comprises communication interface 1302,user interface 1304, and processing system 1306 in communication withcommunication interface 1302 and user interface 1304. Processing node1300 can be configured to determine a communication access node for awireless device. Processing system 1306 includes storage 1308, which cancomprise a disk drive, flash drive, memory circuitry, or other memorydevice. Storage 1308 can store software 1310 which is used in theoperation of the processing node 1300. Storage 1308 may include a diskdrive, flash drive, data storage circuitry, or some other memoryapparatus. Software 1310 may include computer programs, firmware, orsome other form of machine-readable instructions, including an operatingsystem, utilities, drivers, network interfaces, applications, or someother type of software. Processing system 1306 may include amicroprocessor and other circuitry to retrieve and execute software 1310from storage 1008. Processing node 1300 may further include othercomponents such as a power management unit, a control interface unit,etc., which are omitted for clarity. Communication interface 1302permits processing node 1300 to communicate with other network elements.User interface 1304 permits the configuration and control of theoperation of processing node 1300.

Examples of processing node 1300 include controller node 510 and gatewaynode 512. Processing node 1300 can also be an adjunct or component of anetwork element, such as an element of access nodes 104, 106, 504, 506,or 508. Processing node 1300 can also be another network element in acommunication system. Further, the functionality of processing node 1300can be distributed over two or more network elements of a communicationsystem.

The exemplary systems and methods described herein can be performedunder the control of a processing system executing computer-readablecodes embodied on a computer-readable recording medium or communicationsignals transmitted through a transitory medium. The computer-readablerecording medium is any data storage device that can store data readableby a processing system, and includes both volatile and nonvolatilemedia, removable and non-removable media, and contemplates mediareadable by a database, a computer, and various other network devices.

Examples of the computer-readable recording medium include, but are notlimited to, read-only memory (ROM), random-access memory (RAM), erasableelectrically programmable ROM (EEPROM), flash memory or other memorytechnology, holographic media or other optical disc storage, magneticstorage including magnetic tape and magnetic disk, and solid statestorage devices. The computer-readable recording medium can also bedistributed over network-coupled computer systems so that thecomputer-readable code is stored and executed in a distributed fashion.The communication signals transmitted through a transitory medium mayinclude, for example, modulated signals transmitted through wired orwireless transmission paths.

The above description and associated figures teach the best mode of theinvention. The following claims specify the scope of the invention. Notethat some aspects of the best mode may not fall within the scope of theinvention as specified by the claims. Those skilled in the art willappreciate that the features described above can be combined in variousways to form multiple variations of the invention, and that variousmodifications may be made to the configuration and methodology of theexemplary embodiments disclosed herein without departing from the scopeof the present teachings. Those skilled in the art also will appreciatethat various features disclosed with respect to one exemplary embodimentherein may be used in combination with other exemplary embodiments withappropriate modifications, even if such combinations are not explicitlydisclosed herein. As a result, the invention is not limited to thespecific embodiments described above, but only by the following claimsand their equivalents.

What is claimed is:
 1. A method for determining a power option for an access node, comprising: retrieving a plurality of power options for transmitting a first signal from a first access node, wherein a first plurality of wireless devices are in communication with the first access node and the first signal comprises a reference signal; estimating a service metric for each power option, the service metric being based on met application requirements for the first plurality of wireless devices when the first signal is transmitted according to each power option; estimating an interference metric for each power option, the interference metric being based on an overlap between a signal area for the first access node when the first signal is transmitted according to each power option and a signal area for a second access node, wherein estimating the interference metric further comprises: ascertaining locations for a second plurality of wireless devices in communication with the second access node; and estimating, for each of the power options based on transmission of the first signal according to each power option, the interference metric based on the ascertained locations for the second plurality of wireless devices; selecting one of the plurality of power options based on the estimated service metric and the estimated interference metric; and transmitting the first signal according to the selected power option.
 2. The method of claim 1, further comprising selecting one of the plurality of power options when the estimated service metric meets a first criteria and the estimated interference metric meets a second criteria.
 3. The method of claim 2, wherein selecting one of the plurality of power options further comprises: determining a subset of power options from among the plurality of power options, wherein for each of the subset of power options the estimated service metric meets the first criteria and the estimated interference metric meets the second criteria; determining, for each of the subset of power options, a first difference between the estimated service metric and the first criteria and a second difference between the estimated interference metric and the second criteria; and selecting one of the subset of power options based on the first difference and second difference.
 4. The method of claim 2, further comprising: determining an application requirement metric based on a number of wireless devices from among the first plurality of wireless devices that comprise application requirements that are satisfied; and increasing the first criteria when the application requirement metric meets an application requirement criteria.
 5. The method of claim 4, wherein the application requirement criteria comprises one or more of: a quality of service class identifier greater than a first threshold, a guaranteed bit rate greater than a second threshold, a minimum bit rate greater than a third threshold, a maximum permitted data delay less than a fourth threshold, a minimum throughput greater than a fifth threshold, a maximum error rate less than a sixth threshold, and a maximum data loss rate less than a seventh threshold.
 6. The method of claim 1, wherein selecting one of the plurality of power options further comprises: determining, for each of the power options, that the estimated service metric does not meet a first criteria or that the estimated interference metric does not meet a second criteria; determining, for each of a subset of power options, a first difference between the estimated service metric and the first criteria and a second difference between the estimated interference metric and the second criteria; and selecting one of the subset of power options based on the first difference and second difference.
 7. The method of claim 1, wherein estimating the interference metric further comprises: determining a coverage radius for the first signal; estimating, for each power option based on transmission of the first signal according to each power option, an increased coverage radius of the first signal when the first access node performs each power option; determining, for each power option based on transmission of the first signal according to each power option, an overlap area between an estimated increased coverage radius and a coverage radius for a second signal transmitted from the second access node; and estimating, for each power option based on transmission of the first signal according to each power option, the interference metric based on the determined overlap area and the ascertained locations for the second plurality of wireless devices.
 8. The method of claim 1, further comprising: determining updated application requirements for each of a first plurality of wireless devices; estimating, for each power option based on transmission of the first signal according to each power option, an updated service metric based on the updated application requirements; adjusting the selected power option based on the updated service metric and the interference metric.
 9. The method of claim 1, wherein the first signal is used by the first plurality of wireless device for channel estimation when communicating with the first access node.
 10. A system for determining a power option for an access node, comprising: a first access node, a second access node, and a controller, wherein the controller is configured to: retrieve a plurality of power options for transmitting a first signal from a first access node, wherein a first plurality of wireless devices are in communication with the first access node and the first signal comprises a reference signal; estimate a service metric for each power option, the service metric being based on met application requirements for the first plurality of wireless devices when the first signal is transmitted according to each power option; estimate an interference metric for each power option, the interference metric being based on an overlap between a signal area for the first access node when the first signal is transmitted according to each power option and a signal area for a second access node, wherein the estimate for the interference metric further comprises: ascertaining locations for a second plurality of wireless devices in communication with the second access node; and estimating, for each of the power options based on transmission of the first signal according to each power option, the interference metric based on the ascertained locations for the second plurality of wireless devices; select one of the plurality of power options based on the estimated service metric and the estimated interference metric; and transmit the first signal according to the selected power option.
 11. The system of claim 10, wherein the controller is further configured to select one of the plurality of power options when the estimated service metric meets a first criteria and the estimated interference metric meets a second criteria.
 12. The system of claim 11, wherein selecting one of the plurality of power options further comprises: determining a subset of power options from among the plurality of power options, wherein for each of the subset of power options the estimated service metric meets the first criteria and the estimated interference metric meets the second criteria; determining, for each of the subset of power options, a first difference between the estimated service metric and the first criteria and a second difference between the estimated interference metric and the second criteria; and selecting one of the subset of power options based on the first difference and second difference.
 13. The system of claim 11, wherein the controller is further configured to: determine an application requirement metric based on a number of wireless devices from among the first plurality of wireless devices that comprise application requirements that are satisfied; and increase the first criteria when the application requirement metric meets an application requirement criteria.
 14. The system of claim 13, wherein the application requirement criteria comprises one or more of: a quality of service class identifier greater than a first threshold, a guaranteed bit rate greater than a second threshold, a minimum bit rate greater than a third threshold, a maximum permitted data delay less than a fourth threshold, a minimum throughput greater than a fifth threshold, a maximum error rate less than a sixth threshold, and a maximum data loss rate less than a seventh threshold.
 15. The system of claim 10, wherein selecting one of the plurality of power options further comprises: determining, for each of the power options, that the estimated service metric does not meet a first criteria or that the estimated interference metric does not meet a second criteria; determining, for each of a subset of power options, a first difference between the estimated service metric and the first criteria and a second difference between the estimated interference metric and the second criteria; and selecting one of the subset of power options based on the first difference and second difference.
 16. The system of claim 10, wherein estimating the interference metric further comprises: determining a coverage radius for the first signal; estimating, for each power option based on transmission of the first signal according to each power option, an increased coverage radius of the first signal when the first access node performs each power option; determining, for each power option based on transmission of the first signal according to each power option, an overlap area between an estimated increased coverage radius and a coverage radius for a second signal transmitted from the second access node; and estimating, for each power option based on transmission of the first signal according to each power option, the interference metric based on the determined overlap area and the ascertained locations for the second plurality of wireless devices.
 17. The system of claim 10, wherein the controller is further configured to: determine updated application requirements for each of a first plurality of wireless devices; estimate, for each power option based on transmission of the first signal according to each power option, an updated service metric based on the updated application requirements; adjust the selected power option based on the updated service metric and the interference metric.
 18. The system of claim 10, wherein the first signal is used by the first plurality of wireless device for channel estimation when communicating with the first access node. 